Investigating Unipolar Switching in Niobium Oxide Resistive Switches: Correlating Quantized Conductance and Mechanism

TL;DR

This study explores the switching mechanism in Niobium oxide resistive memory devices, revealing atomic-scale filament growth and quantized conductance, which enhances understanding of resistive switching and enables multistate memory applications.

Contribution

It demonstrates atomic-level filament growth and quantized conductance in Niobium oxide RS devices, providing new insights into their switching mechanism.

Findings

Filament grows atom by atom during switching

Stable quantized conductance states observed

Potential for multistate resistive memory

Abstract

Memory devices based on resistive switching (RS) have not been fully realised due to lack of understanding of the underlying switching mechanisms. Nature of ion transport responsible for switching and growth of conducting filament in transition metal oxide based RS devices is still in debate. Here, we investigated the mechanism in Niobium oxide based RS devices, which shows unipolar switching with high ON/OFF ratio, good endurance cycles and high retention times. We controlled the boundary conditions between low-conductance insulating and a high-conductance metallic state where conducting filament (CF) can form atomic point contact and exhibit quantized conductance behaviour. Based on the statistics generated from quantized steps data, we demonstrated that the CF is growing atom by atom with the applied voltage sweeps. We also observed stable quantized states, which can be utilized in multistate switching.